Cervicocerebral arterial dissections are increasingly recognized as a cause of stroke, particularly in young people. The term “cervicocerebral arterial” refers to the arteries in the neck and brain, while the term “dissection” refers to a tear in the inner wall of a major artery. An arterial dissection leads to the intrusion of blood within the layers of the artery wall. Depending upon which layers blood collects, an arterial dissection can cause narrowing of the channel within the artery (termed stenosis), which restricts blood flow, or an aneurysmal dilation, meaning a localized, blood-filled bulge in the artery wall.